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dc.contributor.supervisor Richards, Norman (Mechanical and Manufacturing Engineering) en
dc.contributor.author Balachander, Mettupalayam
dc.date.accessioned 2010-11-03T14:34:29Z
dc.date.available 2010-11-03T14:34:29Z
dc.date.issued 2010-11-03T14:34:29Z
dc.identifier.uri http://hdl.handle.net/1993/4292
dc.description.abstract This research focuses on studying the microstructure of alloy 909, its susceptibility to oxidation at elevated temperatures (~700°C) and substrate coatings compatibility with high velocity oxy fuel (HVOF) sprayed oxidation resistance coatings. The characterization work involved in studying the microstructure of Incoloy 909 at three heat treated conditions namely solution treated condition (ST), commercially recommended solution heat treated and aged condition (STA), and solution treated and over aged condition (STOA) using optical microscopy, analytical scanning electron microscopy, and analytical transmission electron microscopy. The oxidation susceptibility were investigated at elevated temperatures of bare and coated alloy 909 substrates by subjecting test materials to isothermal and thermal cycle testing. The microstructure of alloy 909 in the ST condition showed only the presence of blocky Laves phase. The Laves phase in this alloy is a well known for its grain pinning effect that prevents excessive grain growth. In the STA condition, the microstructure revealed the presence of fine gamma prime, intergranular and intragranular Laves phase and occasionally gamma prime precipitates orienting in a platelet form ready to transition into the epsilon phase. In the STOA condition, the microstructure consisted of Laves phase in inter and intragranular locations, and a copious amount of Widmanstatten type epsilon phase. Incoloy 909 was observed to form oxide scales in both isothermal and cyclic thermal exposures, the oxide scale consisted of distinct outer and inner scales in the micrographs. The comparison base alloy (alloyl 718) used in this study surprisingly did not show any visible presence of oxide scale after 1000 hour exposure at ~700°C. Three coatings (CoNiCrAlY, 718 , and NiAl) were sprayed on alloy 909 and alloy 718 test coupons using the HVOF process to investigate the compatibility of the coatings with the substrate. The test results points out that all the coatings were compatible with 718 substrate and only one coating (NiAl) was found compatible with the Alloy 909 substrate, indicating that the coatings that are compatible with one substrate may not be compatible with another alloy within the same family of alloys. en
dc.format.extent 65068172 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.rights info:eu-repo/semantics/openAccess
dc.subject Alloy 909, Low CTE, Superalloys en
dc.title Microstructural characterization and thermal fatigue study of a coated Incoloy 909 Superalloy en
dc.type info:eu-repo/semantics/doctoralThesis
dc.degree.discipline Mechanical and Manufacturing Engineering en
dc.contributor.examiningcommittee Yannacopoulos, Spiro (Mechanical, UBC, Kamloops) Cahoon, John (Mechanical and Manufacturing Engineering) Shalaby, Ahmed (Civil Engineering) Shanker, Kartik (Mechanical & Manufacturing Engineering) en
dc.degree.level Doctor of Philosophy (Ph.D.) en
dc.description.note February 2011 en


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